Metabolic acidosis may be as protective as hypercapnic acidosis in an ex-vivo model of severe ventilator-induced lung injury: a pilot study

<p>Abstract</p> <p>Background</p> <p>There is mounting experimental evidence that hypercapnic acidosis protects against lung injury. However, it is unclear if acidosis <it>per se </it>rather than hypercapnia is responsible for this beneficial effect. Therefore, we sought to evaluate the effects of hypercapnic (respiratory) versus normocapnic (metabolic) acidosis in an ex vivo model of ventilator-induced lung injury (VILI).</p> <p>Methods</p> <p>Sixty New Zealand white rabbit ventilated and perfused heart-lung preparations were used. Six study groups were evaluated. Respiratory acidosis (RA), metabolic acidosis (MA) and normocapnic-normoxic (Control - C) groups were randomized into high and low peak inspiratory pressures, respectively. Each preparation was ventilated for 1 hour according to a standardized ventilation protocol. Lung injury was evaluated by means of pulmonary edema formation (weight gain), changes in ultrafiltration coefficient, mean pulmonary artery pressure changes as well as histological alterations.</p> <p>Results</p> <p>HPC group gained significantly greater weight than HPMA, HPRA and all three LP groups (P = 0.024), while no difference was observed between HPMA and HPRA groups regarding weight gain. Neither group differ on ultrafiltration coefficient. HPMA group experienced greater increase in the mean pulmonary artery pressure at 20 min (P = 0.0276) and 40 min (P = 0.0012) compared with all other groups. Histology scores were significantly greater in HP vs. LP groups (p < 0.001).</p> <p>Conclusions</p> <p>In our experimental VILI model both metabolic acidosis and hypercapnic acidosis attenuated VILI-induced pulmonary edema implying a mechanism other than possible synergistic effects of acidosis with CO2 for VILI attenuation.</p

Simultaneous laparoscopic management of ureteropelvic junction obstruction and renal lithiasis: the combined experience of two academic centers and review of the literature

Konstantinos G Stravodimos,1 Stilianos Giannakopoulos,2 Stavros I Tyritzis,1 Aristeides Alevizopoulos,1 Stefanos Papadoukakis,1 Stavros Touloupidis,2 Constantinos A Constantinides11Department of Urology, Athens University Medical School, Laiko Hospital, Athens, 2Department of Urology, Democritus University of Thrace, Alexandroupolis, GreeceIntroduction: Approximately one out of five patients with ureteropelvic junction obstruction (UPJO) present lithiasis in the same setting. We present our outcomes of simultaneous laparoscopic management of UPJO and pelvic or calyceal lithiasis and review the current literature.Methods: Thirteen patients, with a mean age of 42.8&plusmn;13.3 years were diagnosed with UPJO and pelvic or calyceal lithiasis. All patients were subjected to laparoscopic dismembered Hynes&ndash;Anderson pyeloplasty along with removal of single or multiple stones, using a combination of laparoscopic graspers, irrigation, and flexible nephroscopy with nitinol baskets.Results: The mean operative time was 218.8&plusmn;66 minutes. In two cases, transposition of the ureter due to crossing vessels was performed. The mean diameter of the largest stone was 0.87&plusmn;0.25 cm and the mean number of stones retrieved was 8.2 (1&ndash;32). Eleven out of 13 patients (84.6%) were rendered stone-free. Complications included prolonged urine output from the drain in one case (Clavien grade I) and urinoma formation requiring drainage in another case (Clavien grade IIIa). The mean postoperative follow-up was 30.2 (7&ndash;51) months. No patient has experienced stone or UPJO recurrence.Conclusion: Laparoscopy for the management of UPJO along with renal stone removal seems a very appealing treatment, with all the advantages of minimally invasive surgery. Concomitant renal stones do not affect the outcome of laparoscopic pyeloplasty, at least in the midterm. According to our results and the latest literature data, we advocate laparoscopic management as the treatment of choice for these cases.Keywords: laparoscopic pyeloplasty, lithiasis, ureteropelvic junction obstructio

Role of percutaneous urinary diversion in malignant and benign obstructive uropathy

Objectives: We evaluated the feasibility and effectiveness of percutaneous urinary diversion in patients with obstructive uropathy, Patients and Methods: A total of 206 percutaneous nephrostomies (PCNs) (right-sided in 54, left in 56, and bilateral in 48) were performed in 102 male and 57 female patients 18 to 94 years old. In 125 patients, malignancy was the underlying cause of the obstruction and in 30, benign disease. In four patients, the cause remained unknown. In most patients (N = 154), the access was guided with both ultrasound and fluoroscopy, Results: Percutaneous nephrostomy was successful in 158 patients (99%). Antegrade ureteral stenting was attempted in 48 patients with a success rate of 81%. Fifteen days postprocedure, the mean urea and creatinine concentrations had declined from 160.8 mg/mL to 63 mg/mL and from 6.9 mg/dL to 2.2 mg/dL, respectively. In 66% of the patients, renal function returned to normal. In 28%, it improved with no need for hemodialysis, while in 6%, there was no improvement. Advanced age and prostate cancer were negative predictive factors for the improvement of renal function, whereas the BUN and creatinine concentrations before the procedure and performance of unilateral v bilateral nephrostomies were not. We did not have severe complications. Three patients received transfusions, and in one patient, a urinoma was drained percutaneously. Patients with malignancy had a median survival of 227 days. Conclusion: Percutaneous urinary diversion under radiologic guidance is a safe and effective procedure for patients with obstructive uropathy

Prolonged ureteral stenting in obstruction after renal transplantation: Long-term results

Background. Renal transplantation is an effective treatment for end-stage renal disease. Ureteral stenosis is the most frequent urologic complication. We report our long-term follow-up results concerning endourologic treatment of ureteral obstruction after renal transplantation. Methods. Between May 1997 and September 2000, 15 patients with renal transplant obstructive uropathy were managed with percutaneous nephrostomy and prolonged ureteral stenting. Results. Petcutaneous nephrostomies were performed successfully in all 15 kidneys. In 13 patients, antegrade ureteral stenting was attempted, which was successful in 11 patients (85%). After prolonged ureteral stenting (mean duration 15 months), the stent was removed in all patients, 90% of whom had no recurrence. During follow-up (36 to 71 months; mean 51), urea, creatinine, sodium, and potassium determinations and ultrasound scans were performed. Success was defined as a reduction in hydronephrosis. No major complications were observed. Conclusions. Modern endourologic procedures have replaced open reconstructive surgery in most patients with ureteral obstruction after renal transplantation, because they may offer a definitive treatment with low morbidity

Obstructive uropathy in the transplanted kidney: Definitive management with percutaneous nephrostomy and prolonged ureteral stenting

Background and Purpose: Renal transplantation is an effective treatment for end-stage renal disease. Ureteral stenosis is the most frequent urologic complication. We report our experience with percutaneous nephrostomy and antegrade ureteral stenting, which may offer a primary and definitive alternative to open surgery. Patients and Methods: Fifteen patients with renal allograft obstructive uropathy were managed with percutaneous nephrostomy and prolonged ureteral stenting. Results: Percutaneous nephrostomies were successfully performed in all 15 kidneys: In 13 patients, antegrade ureteral stenting was attempted, this being successful in 11 (85%). After prolonged ureteral stenting (mean duration 15 months), the stent was removed in eight patients, and six of them (75%) did not have recurrences. During follow-up, urea, creatinine, sodium, and potassium determinations and ultrasound scans were performed, and success was confirmed by the decline of creatinine and reduction in hydronephrosis. No major complication was observed. Conclusion: Percutaneous nephrostomy and ureteral stenting is a safe and effective treatment for renal allograft obstructive uropathy. Prolonged ureteral stenting may offer a definitive treatment with low morbidity